http://www.analog.com/static/imported-files/data_sheets/ADXRS453.pdf
The GyroSetup() message seems to be setting the CHK bit which forces a fault and an error report. Probably not what you want.
The message in Gyro_regular() seems to be another Sensor Data message. At least that one doesn't have the CHK bit set.
It looks like the recommend initialization is a GyroSetup() followed by three Gyro_regular() at 200 mS intervals.
At some point you will probably want to add a read of Register 0 which contains the gyro rate information.